Anionic phthalic acid ester compounds and stain resistant compositions

ABSTRACT

This invention relates to compounds of formula:  
                 
wherein A is an unsaturated alkylene moiety; B the residue of a polyol wherein one hydroxyl moiety is esterified with one carboxyl moiety of the phthalic acid moiety; D is the residue of a polyol wherein one hydroxyl moiety is esterified with another carboxyl moiety of the phthalic acid moiety, and another hydroxyl moiety is esterified with one carboxyl moiety of the unsaturated alkylene moiety; E is the residue of polyol wherein one hydroxyl moiety is esterified with another carboxyl moiety of the unsaturated alkylene moiety; and M is a cation. The compounds can be used alone, or polymerized, or polymerized and combined with other polymers, to form effective stain and soil repellent compositions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to compounds formed from anionic phthalic acidswith diols and unsaturated acids or anhydrides, and to polymers andcopolymers of these monomers with unsaturated acids or esters, whichcompounds, polymers and copolymers can be incorporated into stain resistcompositions suitable for application to fibers, fabric, carpet, and thelike.

2. Description of Related Art

Nylon has had a dramatic effect on both industry and society since itsdiscovery by W. H. Carothers more than fifty years ago. It is estimatedthat 75% of all carpet currently produced in the United States, and 46%of all carpet produced in Europe, is prepared from nylon fiber. Nylonfiber is relatively inexpensive and offers a combination of desirablequalities such as comfort, warmth, and ease of manufacture into a broadrange of colors, patterns, and textures. However, nylon, as well asother polyamide fibers and fabrics, is easily stained by certain naturaland artificial colorants such as those found in coffee, mustard, wine,and soft drinks.

Fluorochemical coatings have been developed that prevent wetting of thecarpet surface, by minimizing chemical contact between the carpetsurface and substances that can stain the carpet, making the substanceeasier to remove. Fluorochemicals also provide a physical barrier tostaining material. Examples of commercially available fluorochemicalcoatings include Teledyne (Daikin), Nuva (Clariant) and Zepel.™. andTeflon.™. (E. I. Du Pont deNemours & Co.). Antron Plus.™. carpetmanufactured by Du Pont contains nylon carpet fibers coated withfluorocarbons.

While fluorochemical coatings are effective in protecting carpet fromsubstances such as soil, they offer little protection from stainsresulting from acid dyes that are found in common household materialssuch as wine, mustard and soft drinks. Acid dyes are bases that bond toprotonated amino sites in the polyamide fiber. A wide variety of methodshave been developed to make polyamide fibers or other fibers withterminal amino groups more resistant to staining by acid dyes. The mostwidely used method involves the application to the polyamide fiber of aformaldehyde phenol or naphthol condensation polymer that has sulfonategroups on the aromatic rings. The sulfonate and hydroxyl groupsionically bond to available protonated amino groups in the polyamidefiber, preventing the protonated amino groups from later bonding tocommon household acid dyes. The polymeric coating also protects thecarpet fiber by creating a barrier of negative electric charge at thesurface of the fiber that prevents like-charged acid dyes frompenetrating the fiber.

Examples of phenol-formaldehyde condensation polymers are described inU.S. Pat. No. 4,501,591 to Ucci, et al., and U.S. Pat. Nos. 4,592,940and 4,680,212 to Blythe, et al. In particular, U.S. Pat. Nos. 4,592,940and 4,680,212 describe a formaldehyde condensation product formed from amixture of sulfonated dihydroxydiphenylsulfone and phenolsulphonic acid,wherein at least 40% of the repeating units contain an —SO₃X radical,and at least 40% of the repeating units are dihydroxydiphenylsulfone.Sulfonated hydroxyaromatic formaldehyde condensation products marketedas stain resistant agents include Erional™ NW (Ciba-Geigy Limited,containing a formaldehyde condensation copolymer ofdihydroxydiphenylsulfone and naphthalene sulfonic acid), Intratex N™(Crompton & Knowles Corp.), Mesitol™ NBS (Mobay Corporation), FX-369(Minnesota Mining & Mfg. Co.), CB-130 (Grifftex Corp.), and Nylofixan P(Clariant Corp., containing a formaldehyde condensation copolymer ofdihydroxydiphenylsulfone and 2,4-dimethylbenzenesulfonic acid). AntronStainmaster™ carpet manufactured by Du Pont contains nylon fibers thathave both a fluorocarbon coating and a sulfonated phenol-formaldehydecondensation polymeric coating.

While sulfonated hydroxyaromatic formaldehyde condensation polymericcoatings reduce the staining of polyamide fibers by acid dyes, they donot impart resistance to staining by compounds such as mustard withtumeric or hot coffee. Further, ultraviolet light and nitrogen dioxidecan yellow the polymers over time. The yellowing can be severe enough toprevent the use of the stain resistant compositions on light shadedtextile articles. Efforts to overcome the discoloration problem arediscussed in U.S. Pat. No. 4,780,099 to Greschler, et al., describingthe reduction of yellowing by application of phenol formaldehydecondensation stain resistant compositions at pH values of 1.5-2.5, andin European Patent Application 87301180.3 by E. I. Du Pont Nemours &Co., describing that polyamide fabrics with improved resistance tostaining as well as discoloration prepared with etherified or acylatedformaldehyde phenol condensation polymers. U.S. Pat. No. 4,822,373 toOlson et al. discloses a stain resisting composition for nylon fibersprepared by blending a partially sulfonated novolak resin with ahomopolymer of methacrylic acid or a copolymer of methacrylic acid withanother ethylenically unsaturated monomer.

U.S. Pat. No. 4,937,123 to Chang et al. discloses a stain resistantcomposition for nylon fibers that includes a homopolymer of methacrylicacid or a copolymer of at least 30% methacrylic acid with anotherethylenically unsaturated monomer.

U.S. Pat. No. 4,940,757 and U.S. Pat. No. 5,061,763 to Moss, et al.,disclose a stain resistant composition prepared by polymerizing anα-substituted acrylic acid in the presence of a sulfonated aromaticformaldehyde condensation polymer using a free radical generating agent.The resulting product imparts to polyamides improved resistance to aciddyes, while exhibiting little discoloration over time, and can be usedat levels of application less than other compositions that are composedof a mere blend of polymethacrylic acid and a sulfonated aromaticformaldehyde condensation polymer.

While the above-described stain resistant compositions impart a degreeof protection to polyamide fibers, many of them are colored solutionsthat actually alter the color of the fiber upon application. Forexample, when a yellow or amber solution is applied to a blue fiber, thefiber can acquire a greenish tint. Given the tremendous volume ofpolyamide fiber used domestically and commercially world-wide, there isa need to provide still improved stain resistant compositions that offera suitable combination of protection from staining by common productssuch as mustard, coffee, and soft drinks, that do not discolor overtime, and that are economical to produce. There is also a need toprovide a stain resistant composition that is sufficiently colorlessthat it does not alter the tint of the dyed fiber.

SUMMARY OF THE INVENTION

In one embodiment, the invention relates to a compound having theformula I, show below:

wherein A is an unsaturated alkylene moiety; B the residue of a polyolwherein one hydroxyl moiety is esterified with one carboxyl moiety ofthe phthalic acid moiety; D is the residue of a polyol wherein onehydroxyl moiety is esterified with another carboxyl moiety of thephthalic acid moiety, and another hydroxyl moiety is esterified with onecarboxyl moiety of the unsaturated alkylene moiety; E is the residue ofpolyol wherein one hydroxyl moiety is esterified with another carboxylmoiety of the unsaturated alkylene moiety; and M is a cation.

In another embodiment, the invention relates to polymers and copolymersformed by the polymerization of the compound of Formula I.

In another embodiment, the invention relates to stain resistcompositions containing these compounds, polymers, or copolymers.

The compound, when reacted with other polymerizable monomers to formcopolymers, provides good repeatability. The resulting polymers orcopolymers, by virtue of the strong anionic character of the sulfonicacid groups, bond strongly to cationic moieties in the polymerstructures of fibers or fabrics, particularly to nylons and wools,providing a durable stain resist composition. This strong anioniccharacter also provides excellent resistance to stain agents, many ofwhich have anionic moieties that are unable to compete for binding siteswith the stain resist polymer, and are electrostatically repelled by theanionic nature of the stain resist polymer.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a series of color photographs showing results of stainresistance testing and nitrous oxide resistance testing of thecompositions according to the invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

As summarized above, one aspect of the invention is the monomer havingthe Formula I:

wherein A is an unsaturated alkylene moiety; B the residue of asubstituted or unsubstituted polyol wherein one hydroxyl moiety isesterified with one carboxyl moiety of the phthalic acid moiety; D isthe residue of a substituted or unsubstituted polyol wherein onehydroxyl moiety is esterified with another carboxyl moiety of thephthalic acid moiety, and another hydroxyl moiety is esterified with onecarboxyl moiety of the unsaturated alkylene moiety; E is the residue ofa substituted or unsubstituted polyol wherein one hydroxyl moiety isesterified with another carboxyl moiety of the unsaturated alkylenemoiety; and M is a cation. Suitable cations include monovalent cations,such as those of alkali metals or ammonium.

The monomer can be prepared by reacting polyols B, D, and E with theanhydride of the unsaturated acid, and the sulfo-substituted phthalicacid in aqueous solution in the presence of a catalyst, such aspara-toluenesulfonic acid or butylstannoic acid, along with dehydrationcatalyst such as TYZOR™ (DuPont) and sodium tetraborate.

Polyol residues B, D, and E may be formed from a C4 to C8, straightchain, branched, or cyclic polyol, and the same polyol may be used toform two or all three residues. Polyol residues B, D, and E may beformed from diols. In a particular embodiment, polyol residues B, D, andE are each formed from the same diol, which is either a 1,6-hexanediol,Neopentyl glycol or a 1,4-cyclohexanedimethanol. Polyol residues B, D,and E may be unsubstituted, or may be substituted by one or moremoieties that will not interfere with either the polymerization of theresulting monomer, or with its ability to bind to fibers or fabrics andprovide stain resistive properties.

As used herein, the term “a phthalic acid” is used to refer to any atleast di-carboxy-substituted phenyl moiety, and includes o-phthalicacid, isophthalic acid, and terephthalic acid. The phthalic acidmoieties used in the monomer of the invention include those that aresubstituted by at least one sulfo group. In a particular embodiment ofthe invention, the phthalic acid moiety of the monomer is that derivedby esterifying 5-sulfoisophthalic acid with the polyols described above.

The unsaturated polycarboxylic acid moiety, which is also esterifiedwith polyols, as described above, is typically a straight chain orbranched dicarboxylic acid containing at least one ethylenic linkage.Suitable examples include maleic acid, fumaric acid, glutaconic acid,itaconic acid, and the like. These acids may be introduced into thereaction mixture as the corresponding anhydrides.

The compounds of the invention can be applied directly to fabric orfibers to provide stain resistant properties thereto, or can bepolymerized or copolymerized as described herein, and the polymers orcopolymers applied directly to fabric or fibers. Alternatively, thecompounds, polymers, or copolymers can be admixed and applied ascompositions or can be combined with other stain resist compounds orcompositions, such as phenol-formaldehyde condensation polymers,polymethacrylic acid, styrene-maleic acid polymers, or poly(meth)acrylicacid IPN with phenol-formaldehyde condensation polymers. Suitableapplication techniques include dipping, foaming or spraying then drying.The compounds may also be exhaust applied, rinsed then dried.

When the compound of formula I is applied directly to the fabric orfiber, it is generally applied in an amount ranging between about 0.5%and 3.0% on weight of fabric. When polymerized into a polymer orcopolymer, amounts ranging between about 0.5% and 3.0% on weight offabric are generally used. When the compound, polymer or copolymer iscombined with another stain resistant compound or composition, such as aphenol-formaldehyde condensation polymer, the resulting compositiongenerally contains between about 30.0 wt % and about 60.0 wt % of thecompound (I), or polymer or copolymer thereof, and about 1.0 wt % toabout 10.0 wt % of additional stain resistant compound or composition.The resulting composition is applied in amounts ranging between about0.5% and about 3.0% on weight of fabric.

EXAMPLE 1

A compound of formula II:

was prepared by combining the following materials in the indicatedproportions (all percentages are by weight unless otherwisespecified): 1. 1,6-hexanediol 30.86% 2. maleic anhydride  8.54% 3.para-toluenesulfonic acid  0.32% 4. Tyzor TBT  0.20% 5.5-sulfoisophthalic acid 23.28% 6. water 36.80%.

In a reactor fitted with distillation apparatus, components 1,2,3, and 4were blended and heated to 100° C. While these components were mixing aslurry of components 5 and 6 was prepared. As soon as the reactionmixture has reached a temperature of 100° C., the slurry of components 5and 6 was added. Heating of the reaction mixture was continued to atemperature of 140° C. while distillate was collected, until the acidnumber of the reaction was less than 40 mg/g KOH. Once the proper acidnumber had been reached, the reaction mixture was cooled to 80° C.Sufficient water was added to the mixture to dilute it to a solidscontent of 63.5%.

EXAMPLE 2

The compound prepared in Example 1 was co-polymerized as follows. 1.Product of Example #1 91.2% 2. Methacrylic acid  5.9% 3. Ammoniumpersulfate  1.0% 4. Water  1.9%

In a reactor fitted with reflux condenser, components 1 and 2 were addedand heated to 60° C. When the reaction temperature reached 60° C. asolution of components 3 and 4 was added. The reaction mixture wasallowed to exotherm and reaction temperature was maintained at 95° C.for 1.5 hours, then cooled.

In Examples 3, 4, and 5, the polymer of Example 2 was formulated intothree stain resist compositions by mixing with the indicatedingredients.

EXAMPLE 3

A stain resist composition was made as follows: 1. Product of Example #245% 2. Myanox 16T-20  2% (UV absorber - Peach State Labs) 3. SodiumXylene Sulfonate 40% 12% 4. Peach State RM-1  5% (Phenol condensate -Peach State Labs) 5. Water 36%

EXAMPLE 4

A stain resist composition was made as follows: 1. Product of Example #245% 2. Polymer 52-DM 35% (Peach State Labs-Pat. Pending) 3. Myanox16T-20  3% (UV absorber - Peach State Labs) 4. Sodium Xylene Sulfonate40% 12% 5. Peach State RM-1  5% (Phenol condensate - Peach State Labs)

EXAMPLE 5

A stain resist composition was made as follows: 1. Product of Example #245% 2. Polymer 52-DM 35% (Peach State Labs-Pat. Pending) 3. Myanox16T-20  2% (UV absorber - Peach State Labs) 4. Sodium Xylene Sulfonate40% 13% 5. Peach State RM-1  5% (Phenol condensate - Peach State Labs)

EXAMPLE 6

The following solutions were prepared and applied to carpet in theamounts indicated. 1. 2. 3. 4. Example #2  37.4 g Example #3  85.2 gExample #4  96.3 g Example #1  34.1 g KAF 400  7.5 g  7.5 g  7.5 g  7.5g Water 955.1 g 907.3 g 896.2 g 958.4 g

Each of these solutions were placed in a blender and mixed until a thickfoam was generated. The foam was then applied to a type 6 nylon loopcarpet sample at 27% wet pick up and squeezed through nip rolls at 45psi. The carpet sample was then dried at 90° C. for 10 minutes.

The treated carpet was then challenged for stain resistance. A piece ofthe treated sample was placed in a Kool Aid solution at 60° C. for 1minute. After 1 minute the piece was continuously rinsed in 40° C. wateruntil no color could be observed in the rinse water. The rinsed piecewas then dried at 90° C. for 10 minutes. After drying the piece wascompared to an AATCC Red 40 Stain Scale. (1—heavily stained, 10—nostain).

Different pieces of the treated sample were exposed to 2 cycles ofnitrous oxide exposure. The exposed piece was then compared to anunexposed sample using the AATCC Gray Scale to evaluate any color change(0—large shade change, 5—no shade change). Additionally, pieces of thetreated sample were also compared to a piece of untreated carpet toevaluate color contribution from the treatment, again using the AATCCGray Scale. The results are provided in Table 1, and color photographsof carpet samples are provided in FIG. 1. In FIG. 1, Row A representstreated carpet without any staining; Row B represents untreated carpetstained with Kool Aid under test conditions; Row C represents treatedcarpet stained with Kook Aid under test conditions; Row D representstreated carpet exposed to 2 cycles of NO₂ testing. Columns 1-4 representthe various Example numbers 1-4, above TABLE 1 1 2 3 4 Kool-Aid Stain 67 9-10 5 NO₂ 4-5 3 3 Treatment 5 5 5 5 Color contribution

EXAMPLE 7

The resulting solution of Example #5 was foam applied to nylon 6broadloom carpet at 2.0% o.w.g. and then tested for stain resistance andyellowing from NO₂. The stain resistance test used was AATCC Method 175.The rating from this test was 9-10. The yellowing from NO₂ was 8 cyclesof exposure using AATCC Method 164. The rating from this test was 4-5.

1-10. (canceled)
 11. A polymer comprising one or more polymerizedmonomers of formula:

wherein A is an unsaturated alkylene moiety; B is the residue of asubstituted or unsubstituted polyol wherein one hydroxyl moiety isesterified with one carboxyl moiety of the phthalic acid moiety; D isthe residue of a substituted or unsubstituted polyol wherein onehydroxyl moiety is esterified with another carboxyl moiety of thephthalic acid moiety, and another hydroxyl moiety is esterified with onecarboxyl moiety of the unsaturated alkylene moiety; E is the residue ofa substituted or unsubstituted polyol wherein one hydroxyl moiety isesterified with another carboxyl moiety of the unsaturated alkylenemoiety; and M is a cation.
 12. The polymer of claim 11, wherein saidpolymer is a copolymer of at least one monomer having the structureshown in formula I and at least one unsaturated carboxylic acid orunsaturated carboxylic acid ester.
 13. The polymer of claim 12, whereinthe unsaturated carboxylic acid or unsaturated carboxylic acid ester isselected from the group consisting of (meth)acrylic acid, alkyl(meth)acrylate, aryl (meth)acrylate, itaconic acid, alkyl itaconate, andaryl itaconate.
 14. The polymer of claim 13, wherein said polymer is acopolymer of a monomer of formula II:

and (meth)acrylic acid.
 15. The polymer of claim 14, wherein the molarratio of methacrylic acid to monomer of formula II ranges from about0.5:1 to about 1.5:1.
 16. (canceled)
 17. A stain resist compositioncomprising an effective amount of at least one polymer of claim
 11. 18.The stain resist composition of claim 17, wherein the composition is inthe form of an aqueous emulsion.
 19. (canceled)
 20. The stain resistcomposition of claim 17, further comprising a blend with one or more;phenol formaldehyde condensation polymers, polymethacrylic acid,styrene-maleic acid polymers, or poly(meth)acrylic acid IPN withphenol-formaldehyde condensation polymers.
 21. (canceled)
 22. A methodof imparting stain resistance to fabric or fiber, comprising contactingthe fabric or fiber with the composition of claim
 17. 23. (canceled) 24.A method of imparting stain resistance to fabric or fiber, comprisingcontacting the fabric or fiber with the composition of claim 20.